Our October issue of Immunology in the News highlights emerging roles for immunology in medical prognosis and the eventual identification of pathways for disease prevention and recovery.
Two articles that discuss this new prognosis field merit discussion here, but please do not let this focus discourage you from examining other fascinating developments in this issue concerning cancer, AIDS, influenza, Crohn’s disease and fundamental immunology.
Prognosis of Huntington’s disease
Our coverage of the scientific literature (on page 8 of our print issue) highlights a paper from the Journal of Experimental Medicine on the prognosis of Huntington’s disease. Woody Guthrie, the American folk music pioneer and composer of “This Land Is Your Land,” was famously afflicted with this neurological disorder, which causes uncontrolled movements in adults. The disease develops because of an abnormality in a gene named huntingtin. The abnormal gene causes brain cells to malfunction, which leads to the development of the symptoms of Huntington’s.
Now, a group of scientists from the U.K., Sweden, Canada and the U.S. reports that, surprisingly, the abnormal huntingtin gene also alters the function of immune cells. Led by Sarah Tabrizi, the group shows that blood cells from patients with Huntington’s disease produce high levels of cytokines such as interleukin-6. These elevated levels can be detected in the blood an average of 16 years before the patient develops overt symptoms of brain malfunction. Cytokines were also particularly abundant in several post-mortem samples of brain tissue.
The authors propose that cytokines produced by immune cells help to promulgate the illness. There are dozens of different cytokines, and some already are known to alter the functions of brain cells. The Huntington’s disease findings will very likely stimulate additional studies to determine whether specific cytokines can help forecast the development and outcome of other neurological diseases.
Predicting resistance to cancer
The Science magazine article “Directing a Life in Science” profiles the career of Olivera “Olja” Finn, head of immunology at the University of Pittsburgh. Finn has been a leader in the identification of cancer antigens recognized by the immune system and used as logical components of cancer vaccines.
As Finn outlines in her recent Presidential Address to the American Association of Immunologists, accessible at www.dana.org/immunology, her research is uncovering changes in anti-cancer immunity that seem to predict the capacity of an individual to defend himself or herself against the development of cancer.
Finn first looked for the development of antibodies to cancer cells in patients with “premalignancy,” that is, cell changes on the road to cancer that were not yet malignant. These antibodies recognized components of the cancer cell that were normal (i.e. genetically unaltered) but that could be expressed at higher levels in a cancerous patient.
Surprisingly, when Finn and her colleagues cast their net more broadly, immune changes could be identified in otherwise healthy individuals. The research shows that the antibodies can develop as a byproduct of infection and injury. Finn proposes that these immune responses actually work to prevent the development of cancer. In addition to predicting how some patients might become more resistant to cancer, the findings argue in favor of inducing immune responses sooner rather than later, in order to retard or prevent the development of cancer.
Of course, immunology has always been a vital part of medical diagnosis. Immune approaches, particularly the current use of antibodies, provide specific tests to determine whether a patient is already infected with a particular microbe such as the AIDS virus, or whether a patient has an autoimmune disease such as systemic lupus erythematosus.
However, these studies illustrate a new realm, that of medical prognosis—predicting whether a disease develops in a patient and whether it will be resisted. Prognosis not only helps to understand how disease comes about, but it also directs researchers to better pathways for prevention and treatment.